Recent studies have shown that mechanical factors can direct stem cell fate in vitro, even in the absence of biochemical
factors. Two-photon laser polymerization was applied here to fabricate ultra-precise 3D micro-scaffolds with different
architectures and pore sizes able to structurally interact with cells at the single-cell scale. Our experiments have shown
that randomly seeded mesenchymal stem cells systematically colonize the internal volumes of 3D scaffolds and
proliferate, while showing a roundish morphology. Even if stem cell mechanobiology is a very complex field, this study
shows how mechanical interactions studied in a 3D micro-architecture at a single cell scale may influence stem cells
response.